Right now I have the racing beat header and presilencer combo and since I already have just about every god damn thing I can put on this car, I figured getting the mazdatrix true dual exhaust would be a decent gain, but since it is 1400 smackers I want at least a noticable increase. And emissions are out of the question.

 

I want to know the same damn thing. I was going to just buy the headers & presilencer but couldn't even decide on a catback. So I decided to just save for the true duals. Anyone already have this?

 

You can expect a gain of 4% to 8% for the true dual over a single exhaust. But it is *much* louder.